377 research outputs found
An investigation of the factors affecting middle school mathematics students\u27 ability to solve unfamiliar problems involving familiar mathematics concepts
The Relationship between Stock Price and EPS: Evidence Based on Taiwan Panel Data
In this study, we use panel cointegration methods to investigate the relationship between stock prices and earnings-per-share (EPS). Furthermore, we consider whether stock prices respond to EPS under the different level of growth rate of operating revenue. The empirical result indicated that the cointegration relationship existed between stock prices and EPS in the long-run. Furthermore, we found that for the firm with a high level of growth rate, EPS has less power in explaining the stock prices however, for the firm with a low level of growth rate, EPS has a strong impact in stock prices.Earnings Response Coefficient (ERC)
Asiatic acid, a triterpene, induces apoptosis and cell cycle arrest through activation of extracellular signal-regulated kinase and p38 mitogen-activated protein kinase pathways in human breast cancer cells
ABSTRACT This study first investigates the anticancer effect of asiatic acid in two human breast cancer cell lines, MCF-7 and MDA-MB-231. Asiatic acid exhibited effective cell growth inhibition by inducing cancer cells to undergo S-G2/M phase arrest and apoptosis. Blockade of cell cycle was associated with increased p21/ WAF1 levels and reduced amounts of cyclinB1, cyclinA, Cdc2, and Cdc25C in a p53-independent manner. Asiatic acid also reduced Cdc2 function by increasing the association of p21/WAF1/Cdc2 complex and the level of inactivated phospho-Cdc2 and phospho-Cdc25C. Asiatic acid treatment triggered the mitochondrial apoptotic pathway indicated by changing Bax/Bcl-2 ratios, cytochrome c release, and caspase-9 activation, but it did not act on Fas/Fas ligand pathways and the activation of caspase-8. We also found that mitogen-activated protein kinases (MAPKs), extracellular signal-regulated kinase (ERK1/2), and p38, but not c-Jun NH 2 -terminal kinase (JNK), are critical mediators in asiatic acid-induced cell growth inhibition. U0126 [1,4-diamino-2,3-dicyano-1,4-bis(2-aminophenylthio)butadiene] or SB203580 [4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl)-1H-imidazole], specific inhibitors of mitogen-activated protein kinase kinase and p38 kinase activities, significantly decreased or delayed apoptosis. Asiatic acid was likely to confine the breast cancer cells in the S-G2/M phase mainly through the p38 pathway, because both SB203580 and p38 small interfering RNA (siRNA) inhibition significantly attenuated the accumulation of inactive phospho-Cdc2 and phospho-Cdc25C proteins and the cell numbers of S-G2/M phase. Moreover, U0126 and ERK siRNA inhibition completely suppressed asiatic acid-induced Bcl-2 phosphorylation and Bax up-regulation, and caspase-9 activation. Together, these results imply a critical role for ERK1/2 and p38 but not JNK, p53, and Fas/Fas ligand in asiatic acid-induced S-G2/M arrest and apoptosis of human breast cancer cells
The molecular gas kinematics in the host galaxy of non-repeating FRB 180924B
Fast radio bursts (FRBs) are millisecond-duration transients with large
dispersion measures. The origin of FRBs is still mysterious. One of the methods
to comprehend FRB origin is to probe the physical environments of FRB host
galaxies. Mapping molecular-gas kinematics in FRB host galaxies is critical
because it results in star formation that is likely connected to the birth of
FRB progenitors. However, most previous works of FRB host galaxies have focused
on its stellar component. Therefore, we, for the first time, report the
molecular gas kinematics in the host galaxy of the non-repeating FRB 180924B at
. Two velocity components of the CO (3-2) emission line are detected
in its host galaxy with the Atacama Large Millimeter/submillimeter Array
(ALMA): the peak of one component ( km s) is near the centre of
the host galaxy, and another ( km s) is near the FRB position.
The CO (3-2) spectrum shows asymmetric profiles with A , where A is the peak flux density ratio between the two
velocity components. The CO (3-2) velocity map also indicates an asymmetric
velocity gradient from km s to 8 km s. These results
indicate a disturbed kinetic structure of molecular gas in the host galaxy.
Such disturbed kinetic structures are reported for repeating FRB host galaxies
using HI emission lines in previous works. Our finding indicates that
non-repeating and repeating FRBs could commonly appear in disturbed kinetic
environments, suggesting a possible link between the gas kinematics and FRB
progenitors.Comment: 5 pages, 4 figures, Accepted for publication in MNRAS,
https://www.youtube.com/watch?v=CldxLE7Pdwk&t=1
Osthole-Mediated Cell Differentiation through Bone Morphogenetic Protein-2/p38 and Extracellular Signal-Regulated Kinase 1/2 Pathway in Human Osteoblast Cells
Detecting Web-Based Botnets Using Bot Communication Traffic Features
Web-based botnets are popular nowadays. A Web-based botnet is a botnet whose C&C server and bots use HTTP protocol, the most universal and supported network protocol, to communicate with each other. Because the botnet communication can be hidden easily by attackers behind the relatively massive HTTP traffic, administrators of network equipment, such as routers and switches, cannot block such suspicious traffic directly regardless of costs. Based on the clients constituent of a Web server and characteristics of HTTP responses sent to clients from the server, this paper proposes a traffic inspection solution, called Web-based Botnet Detector (WBD). WBD is able to detect suspicious C&C (Command-and-Control) servers of HTTP botnets regardless of whether the botnet commands are encrypted or hidden in normal Web pages. More than 500âGB real network traces collected from 11 backbone routers are used to evaluate our method. Experimental results show that the false positive rate of WBD is 0.42%
Effects of a Chinese Herbal Medicine, Guan-Jen-Huang (Aeginetia indica Linn.), on Renal Cancer Cell Growth and Metastasis
Aeginetia indica Linn. (Guan-Jen-Huang, GJH), a traditional Chinese herb, has the potential to be an immunomodulatory agent. The purpose of this study was to explore the effect of GJH in the treatment of renal cancer. Concentration-effect curves for the influence of GJH on cellular proliferation showed a biphasic shape. Besides, GJH had a synergistic effect on cytotoxicity when combined with 5-fluorouracil (5-FU)which may be due to the alternation of the chemotherapeutic agent resistance-related genes and due to the synergistic effects on apoptosis. In addition, treatment with GJH extract markedly reduced 786-O cell adherence to human umbilical vein endothelial cells (HUVECs) and decreased 786-O cell migration and invasion. In a xenograft animal model, GJH extract had an inhibitory effect on tumor cell-induced metastasis. Moreover, western blot analysis showed that the expression of intercellular adhesion molecule-1 (ICAM-1) in 786-O cells was significantly decreased by treatment with GJH extract through inactivation of nuclear factor-ÎșB (NFâÎșB). These results suggest that GJH extract has a synergistic effect on apoptosis induced by chemotherapeutic agents and an inhibitory effect on cell adhesion, migration, and invasion, providing evidence for the use of water-based extracts of GJH as novel alternative therapeutic agents in the treatment of human renal cancer
Antiinflammatory and Antioxidant Flavonoids and Phenols from Cardiospermum halicacabum (ćć°éŽ DĂ o DĂŹ LĂng)
ABSTRACTSeventeen compounds, quercetin-3-O-α-l-rhamnoside (1), kaempferol-3-O-α-l-rhamnoside (2), apigenin-7-O-ÎČ-d-glucuronide (3), apigenin 7-O-ÎČ-d-glucuronide methyl ester (4), apigenin 7-O-ÎČ-d-glucuronide ethyl ester (5), chrysoeriol (6), apigenin (7), kaempferol (8), luteolin (9), quercetin (10), methyl 3,4-dihydroxybenzoate (11), p-coumaric acid (12), 4-hydroxybenzoic acid (13), hydroquinone (14), protocathehuic acid (15), gallic acid (16), and indole-3-carboxylic acid (17), were isolated from the ethanol extract of Taiwanese Cardiospermum halicabum. All chemical structures were determined by physical and extensive spectroscopic analyses such as 1H Nuclear Magnetic Resonance spectroscopy (NMR), 13C NMR, 1H-1H Correlation spectroscopy (1H-1H COSY), Heteronuclear Multiple Quantum Coherence spectroscopy (HMQC), Heteronuclear Multiple-bond Correlation spectroscopy (HMBC), and Nuclear Overhauser Effect spectroscopy (NOESY), as well as comparison with literature values. Furthermore, the High-Performance Liquid Chromatography-Photodiode Array Detector (HPLC-DAD) fingerprint profile was established for the determination of major constituents in the EtOAc extract and retention times of the isolated compounds. All isolated compounds were also evaluated for antiinflammatory and antioxidant activities
Identification of Postoperative Prognostic MicroRNA Predictors in Hepatocellular Carcinoma
Comparison of microRNA (miRNA) expression profiles in the noncancerous liver tissues adjacent to hepatocelluar carcinomas (HCCs) was a strategy to identify postoperative prognostic predictors in this study. Expression profiles of 270 miRNAs were determined in the paraneoplastic liver tissues of 12 HCC patients with known postoperative prognosis. A panel of candidate miRNA predictors was identified. The prognostic predictive value of these candidate miRNAs was then verified in 216 postoperative HCC patients. Univariate analysis identified 8 and 3 miRNA predictors for recurrence-free (RFS) and overall (OS) survivals, respectively. Multivariate analysis revealed high expression levels of miR-155 (HR, 2.002 [1.324â3.027]; Pâ=â.001), miR-15a (HR, 0.478 [0.248â0.920]; Pâ=â.027), miR-432 (HR, 1.816 [1.203â2.740]; Pâ=â.015), miR-486-3p (HR, 0.543 [0.330â0.893]; Pâ=â.016), miR-15b (HR, 1.074 [1.002â1.152]; Pâ=â.043) and miR-30b (HR, 1.102 [1.025â1.185]; Pâ=â.009) were significantly associated with RFS. When clinicopathological predictors were included, multivariate analysis revealed that tumor number and miR-432, miR-486-3p, and miR-30b expression levels remained significant as independent predictors for RFS. Additionally, expression knockdown of miR-155 in J7 and Mahlavu hepatoma cells resulted in decreased cell growth and enhanced cell death in xenograft tumors, suggesting an oncogenic effect of miR-155. In conclusion, significant prognostic miRNA predictors were identified through examination of miRNA expression levels in paraneoplastic liver tissues. Functional analysis of a miRNA predictor, miR-155, suggested that the prognostic miRNA predictors identified under this strategy could serve as potential molecular targets for anticancer therapy
Genetic polymorphisms in glutathione S-transferase (GST) superfamily and risk of arsenic-induced urothelial carcinoma in residents of southwestern Taiwan
<p>Abstract</p> <p>Background</p> <p>Arsenic exposure is an important public health issue worldwide. Dose-response relationship between arsenic exposure and risk of urothelial carcinoma (UC) is consistently observed. Inorganic arsenic is methylated to form the metabolites monomethylarsonic acid and dimethylarsinic acid while ingested. Variations in capacity of xenobiotic detoxification and arsenic methylation might explain individual variation in susceptibility to arsenic-induced cancers.</p> <p>Methods</p> <p>To estimate individual susceptibility to arsenic-induced UC, 764 DNA specimens from our long-term follow-up cohort in Southwestern Taiwan were used and the genetic polymorphisms in GSTM1, GSTT1, GSTP1 and arsenic methylation enzymes including GSTO1 and GSTO2 were genotyped.</p> <p>Results</p> <p>The GSTT1 null was marginally associated with increased urothelial carcinoma (UC) risk (HR, 1.91, 95% CI, 1.00-3.65), while the association was not observed for other GSTs. Among the subjects with cumulative arsenic exposure (CAE) â„ 20 mg/L*year, the GSTT1 null genotype conferred a significantly increased cancer risk (RR, 3.25, 95% CI, 1.20-8.80). The gene-environment interaction between the GSTT1 and high arsenic exposure with respect to cancer risk was statistically significant (multiplicative model, <it>p </it>= 0.0151) and etiologic fraction was as high as 0.86 (95% CI, 0.51-1.22). The genetic effects of GSTO1/GSTO2 were largely confined to high arsenic level (CAE â„ 20). Diplotype analysis showed that among subjects exposed to high levels of arsenic, the AGG/AGG variant of GSTO1 Ala140Asp, GSTO2 5'UTR (-183)A/G, and GSTO2 Asn142Asp was associated with an increased cancer risk (HRs, 4.91, 95% CI, 1.02-23.74) when compared to the all-wildtype reference, respectively.</p> <p>Conclusions</p> <p>The GSTs do not play a critical role in arsenic-induced urothelial carcinogenesis. The genetic effects of GSTT1 and GSTO1 on arsenic-induced urothelial carcinogenesis are largely confined to very high exposure level.</p
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